Old School Green Beans Classic

Featured in: Comfort Baking

This comforting side blends tender green beans with a savory mushroom sauce made from butter, garlic, and cream. The dish is topped multiple times with crispy fried onions for a crunchy finish. It's baked until bubbling and golden, offering a nostalgic flavor that pairs beautifully with traditional holiday meals or family gatherings. Simple to prepare and packed with familiar textures and tastes, it’s a flavorful addition to any festive spread.

Updated on Tue, 11 Nov 2025 13:59:00 GMT
Golden-brown Old-School Green Bean Casserole bubbling in a baking dish, ready for serving alongside a holiday meal. Save
Golden-brown Old-School Green Bean Casserole bubbling in a baking dish, ready for serving alongside a holiday meal. | butterhearth.com

A nostalgic, creamy side dish featuring tender green beans, savory mushrooms, and crispy fried onions—a classic for holiday feasts and family dinners.

This is the green bean casserole I grew up with at every Thanksgiving and Christmas. The scratch-made sauce and generous topping of fried onions always bring me back to festive family dinners.

Ingredients

  • Fresh green beans: 900 g (2 lb), trimmed and cut into 5 cm (2-inch) pieces (or substitute with 900 g frozen cut green beans, thawed and drained)
  • Unsalted butter: 2 tbsp
  • Cremini or button mushrooms: 250 g (9 oz), sliced
  • Yellow onion: 1 small, finely chopped
  • Garlic cloves: 2, minced
  • All-purpose flour: 2 tbsp
  • Whole milk: 240 ml (1 cup)
  • Heavy cream: 120 ml (½ cup)
  • Low-sodium vegetable broth: 120 ml (½ cup)
  • Salt: 1 tsp
  • Black pepper: ½ tsp
  • Ground nutmeg (optional): ½ tsp
  • Crispy fried onions: 150 g (1½ cups), store-bought or homemade

Instructions

Preheat the oven:
Preheat the oven to 180°C (350°F).
Blanch the green beans:
Bring a large pot of salted water to a boil. Add green beans and cook for 5 minutes until just tender but still bright green. Drain and immediately rinse under cold water to stop cooking. Set aside.
Cook the vegetables:
In a large skillet over medium heat, melt the butter. Add mushrooms and cook for 5-6 minutes until tender and browned. Add onion and garlic, cooking for another 2-3 minutes until softened.
Make the sauce:
Stir in the flour and cook for 1 minute, stirring constantly. Gradually whisk in milk, cream, and broth. Bring to a simmer and cook until thickened, about 5 minutes. Season with salt, pepper, and nutmeg (if using).
Combine beans and sauce:
Add the drained green beans to the skillet and toss to coat evenly in the sauce.
Assemble the casserole:
Transfer the mixture to a 2-liter (2-quart) baking dish. Sprinkle half of the crispy fried onions on top.
Bake:
Bake for 25 minutes until bubbling. Remove from oven, top with remaining onions, and bake for 5-7 minutes more until golden and crisp.
Serve:
Let cool for 5 minutes before serving.
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| butterhearth.com

Every holiday, my family requests this green bean casserole. It's always the first side to disappear, especially when the kids get extra crispy onions on their servings.

Serving Suggestions

This casserole pairs wonderfully with roast turkey, baked ham, or chicken. A bright cranberry sauce or a crisp salad rounds out the meal perfectly.

Make Ahead & Storage

Assemble the casserole through step 6 and refrigerate, tightly covered, for up to 24 hours. Add the onions and bake just before serving. Leftovers keep in the fridge for 3 days, reheated until hot.

Dietary & Allergen Info

This recipe contains dairy, gluten, and soy. For a gluten-free version, use gluten-free flour and fried onions. Always check store-bought ingredient labels.

Creamy homemade Old-School Green Bean Casserole with a crispy onion topping, perfect for comforting family dinners. Save
Creamy homemade Old-School Green Bean Casserole with a crispy onion topping, perfect for comforting family dinners. | butterhearth.com

This old-school green bean casserole tastes like home in every bite. Make it your own with cheese or extra mushrooms.

Recipe Questions

How do I keep green beans tender yet crisp?

Blanch green beans in boiling salted water for about 5 minutes until just tender, then shock them in cold water to stop cooking and preserve their color and crunch.

Can I use frozen green beans?

Yes, thaw and drain frozen green beans thoroughly before cooking to avoid excess moisture in the sauce.

What gives the sauce its creamy texture?

Butter, flour, milk, and cream are combined and cooked to form a smooth, velvety sauce enriched with sautéed mushrooms and onions.

How do I achieve a crispy topping?

Sprinkle fried onions on top twice during baking—once before baking and again midway—to ensure a golden, crisp finish.

Can this dish be prepared ahead?

Assemble up to the baking step, refrigerate for up to 24 hours, then add topping and bake fresh before serving.

What flavors complement this dish well?

Its creamy, savory profile pairs beautifully with roast turkey, chicken, or other hearty main courses.

Old School Green Beans Classic

Tender green beans in a creamy mushroom sauce with crispy fried onion topping.

Prep duration
15 min
Time to cook
35 min
Complete duration
50 min
Created by Grace Mitchell


Skill Level Easy

Heritage American

Output 6 Portions

Dietary considerations Meat-Free

Components

Vegetables

01 2 lb fresh green beans, trimmed and cut into 2-inch pieces (or frozen, thawed and drained)

Sauce Base

01 2 tablespoons unsalted butter
02 9 oz cremini or button mushrooms, sliced
03 1 small yellow onion, finely chopped
04 2 garlic cloves, minced
05 2 tablespoons all-purpose flour
06 1 cup whole milk
07 ½ cup heavy cream
08 ½ cup low-sodium vegetable broth
09 1 teaspoon salt
10 ½ teaspoon black pepper
11 ½ teaspoon ground nutmeg (optional)

Topping

01 1½ cups crispy fried onions (store-bought or homemade)

Directions

Stage 01

Preheat Oven: Set the oven temperature to 350°F.

Stage 02

Cook Green Beans: Bring a large pot of salted water to a boil. Add green beans and cook for 5 minutes until just tender but still bright green. Drain and rinse under cold water to halt cooking; set aside.

Stage 03

Sauté Vegetables: In a large skillet over medium heat, melt butter. Add mushrooms and cook for 5-6 minutes until tender and browned. Add onion and garlic; cook an additional 2-3 minutes until softened.

Stage 04

Prepare Sauce: Stir in flour and cook for 1 minute stirring constantly. Gradually whisk in milk, cream, and vegetable broth. Simmer until thickened, approximately 5 minutes. Season with salt, pepper, and nutmeg if using.

Stage 05

Combine Green Beans and Sauce: Add the drained green beans to the skillet and toss to coat evenly with the sauce.

Stage 06

Assemble Casserole: Transfer the mixture to a 2-quart baking dish. Sprinkle half of the crispy fried onions evenly over the top.

Stage 07

Bake First Stage: Bake for 25 minutes until the casserole is bubbling.

Stage 08

Add Remaining Topping and Finish Baking: Remove from oven, sprinkle remaining fried onions on top, and bake for an additional 5 to 7 minutes until golden and crisp.

Stage 09

Rest Before Serving: Allow the dish to cool for 5 minutes before serving.

Necessary tools

  • Large pot
  • Colander
  • Large skillet
  • Whisk
  • 2-quart baking dish
  • Oven

Allergy details

Review each component for potential allergens and consider consulting with a healthcare provider if you're unsure about certain ingredients.
  • Contains milk (dairy), wheat (gluten in flour and fried onions), and possibly soy (in store-bought fried onions). Verify labels carefully.

Nutritional information (per portion)

These values are estimates only and shouldn't replace professional medical guidance.
  • Energy Value: 265
  • Fats: 15 g
  • Carbohydrates: 25 g
  • Protein Content: 6 g